package newcoder.lx_提取不重复的整数;

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

/**
 * @Author Mr.wang
 * @Description
 * @Date 2020-04-11
 */
public class Main1 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNext()) {
            String line = scanner.nextLine();
            StringBuilder newLine = new StringBuilder(line);
            newLine.reverse();
            Set<String> sets = new HashSet<>();
            for (int i = 0; i < newLine.length(); i++) {
                sets.add(newLine.toString().charAt(i)+"");
            }
            System.out.println(sets.toString());
        }
    }
}
